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MRCS A: Pathology II > Haematology > Flashcards

Flashcards in Haematology Deck (42)
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1
Q

Anaemia (Microcytic)

A

Iron deficiency

  • Malabsorption
  • Chronic blood loss
  • Decreased dietary intake
  • Increased demand

Anaemia of chronic disease

Thalassaemia

2
Q

Anaemia (Normocytic)

A
Acute blood loss
Anaemia of chronic disease
Endocrine disease
Malignancy
Haemolytic anaemia
3
Q

Anaemia (Macrocytic)

A

Megaloblastic

  • Folate deficiency
  • B12 deficiency
  • Pernicious anaemia
  • Crohn’s disease
  • Gastrectomy, ileal resection
  • Alcohol

Drugs

  • Azathioprine
  • hydroyurea
  • Methotrexate

Non-megaloblastic anaemia

  • liver disease
  • alcohol
  • pregnancy
  • hypothyroidism
4
Q

Polycythaemia primary

A

Hb>18g/dl males

Hb>16g/dl females

5
Q

Polycythaemia secondary

A
Appropriate increase in erythropoietin
- High altitude
- cardiac disease
- Pulmonary disease
Smoking

Inappropriate

  • Renal/hepatic cancer
  • cerebellar haemangioblastoma
  • renal transplant
  • uretine fibroblasts

Relative

  • dehydration
  • burns
6
Q

Neutrophilia

A

Acute infection
- Bacteria, fungi, spirochaetes, viruses, rickettsiae

Inflammation
- Burns, trauma, MI, gout, glomerulonephritis, collagen vascular disorders, hypersensitivity

Metabolic

  • DKA
  • Pre-eclampsia
  • Uraemia
7
Q

Thrombocytopaenia (5)

A
Platelet dysfunction
DIC
Thrombotic thrombocytopenic purpura
Haemolytic uraemic syndrome
Idiopathic thrombotic purpura
8
Q

Platelet dysfunction

A

Most often due to iatrogenic causes e.g. aspirin/warfarin.

Aspirin should be stopped 14 days prior to operation

9
Q

Disseminated Intravascular Coagulation

A

Simulataneous activation of coagulation and fibrinolytic systems in the body causing microvascular thrombosis, fibrin deposition and bleeding due to clotting factors and fibrinolysis

10
Q

Thrombotic thrombocytopenic purpura

A
  • Usually affects young adults
  • Deposition of hyaline thrombi in small vessels causes microangiopathic widespread haemolysis
  • Renal failure
  • Neurological disturbance
11
Q

Haemolytic uraemic syndrome

A

Usually post illness e.g. URTI and GI infections such as E.Coli

  • Microangiopathic haemolysis
  • Thrombocytopaenia
  • Acute renal failure
12
Q

Idiopathic thrombotic purpura

A

Autoimmune destruction of platelets secondary to IgG

  • Acute: Post viral e.g. children, Henoch-Schonlein purpura
  • Chronic (Adults, female predominance, treated with high dose steroids, rarely splenectomy)
13
Q

Thrombocytosis (Primary)

A

Essential thrombocythaemia

  • PCV
  • Bruising, bleeding, cerebrovascular
  • Splenic atrophy due to recurrent thromboses after initial hypertrophy
14
Q

Thrombocytosis (Secondary)

A
  • Haemorrhage
  • Connective disorders
  • Surgery
  • Splenectomy
  • Malignancy
  • Myeloproliferative disorders
15
Q

Sickle Cell Disease I

A

Hb is made of 2 Alpha and 2 Beta chains

Beta chain abnormalities lead to sickle cell haemoglobin creating HbS (Glutamine @ position 6 on Beta chain is replaced by Valine) as Hb AS or HbSS

16
Q

Sickle Cell Disease II

A

Deoxygenated HbS is insoluble and polymerises causing the red blood cells to form rigid inflexible shapes. Initially responsive to oxygen therapy and reversible.

Causes:
-Haemolytic anaemia–gallstone pigmentation

-Vaso-occlusive crises
Infarction, severe ischaemic pain seen in the bones, chest , kidney, liver and penis (Priapism)

Increased susceptibility to infections such as streptococcus pneumoniae, salmonella meningitis, renal failure and blindness

17
Q

Thalassaemia causes

A

Defective globin chain synthesis

Haemolysis, anaemia and ineffective erythropoiesis

Beta-thalassaemia major (homozygous 3-4 defective)
Beta-thalassaemia minor (heterozygous 2 defective)
Alpha thalassaemia (4 chains defective)
18
Q

Beta thalassaemia trait

A

Symptomless microcytosis
Mild anaemia

Severe anaemia from approx 3 months with failure to thrive and requiring regular transfusions with the following occuring:

  • Extramedullary haemopoiesis
  • hepatosplenomegaly
  • Frontal bossing
  • Characteristic appearance
  • Requires blood transfusion to keep Hb above 10g/dl
  • Desferrioxamine acts as iron chelation
19
Q

Anisocytosis

Poikilocytosis

A

A: Variation in size

P: Variation in shape

20
Q

Poikilocytosis (5)

A

Spherocytosis (hereditary)

Elliptocytosis (Hereditary and iron deficiency)

Target cells (Liver disease, obstructive jaundice, hyposplenism)

Irregularly contracted cells (Oxidant damage)

Sickle cells

21
Q

Haemolytic anaemia causes (II)

A

Inherited and Acquired

22
Q

Haemolytic anaemia inherited

A

Hereditary spherocytosis

Sickle cell anaemia

Pyruvate kinase pathway

G6PD deficiency

23
Q

Haemolytic anaemia acquired

A

Autoimmune haemolytic anaemia

Oxidant damage e.g. dapsone

Microangiopathic haemolytic anaemia

24
Q

Folate deficiency

A

Megaloblastic anaemia

Neural tube defects (Spina bifida, anencephaly)

25
Q

B12 deficiency causes

A

Crohn’s/Coeliac’s disease

Pernicious anaemia

Gastrectomy

26
Q

B12 deficiency consequences (Absorbed in stomach via IF and then ileum)

A

Megaloblastic anaemia

Bilateral peripheral neuropathy

Subacute combined degeneration of the cord (Parasthesia, muscle weakness, difficulty walking, visual and cognitive impairment, Hyporeflexia and upgoing plantars)

Optic atrophy

Dementia

27
Q

Schilling test

A

1) Replenish Vit B12 stores
2) Radiolabelled B12
3) Measure urine B12
4) If normal urinary B12 present
4b) If depletion no urinary B12
5) Repeat with intrinsic factor
6) If rectified–>pernicious anaemia

28
Q

Antithrombotic factors

A

Prostacyclin
Thrombomodulin
Nitric oxide
Tissue plasminogen activator (tPA)

29
Q

Prostacyclin

A

Inhibitis platelet aggregation and acts as a vasodilator

30
Q

Thrombomodulin

A

Glycoprotein situated on endothelial cells, combines with thrombin to a activate protein C (co-factor to protein S) which degrades Factor Va and VIIIa. hence fibrin formation is reduced

31
Q

Nitric oxide

A

Vasodilator

Inhibits platelet aggregation and adhesion

32
Q

tPA

A

Regulates fibrinolysis

33
Q

Thrombotic factors

A

Von Willebrand factor
Platelet activating factor
Plasminogen activator inhibitor

34
Q

Von willebrand factor

A

Platelet aggregator

Factor VIII activator

35
Q

Platelet activating factor

A

Platelet aggregation

36
Q

Plasminogen activator inhibitor

A

Inhibits tPA

37
Q

Platelets

A
  1. Vascular injury
  2. Platelets bind to collagen via vWF
  3. activation causes alpha and dense granules to release fibrinogen and ADP causing aggregation and thromboxane A2 causing vasoconstriction
  4. Platelet plug formed
  5. Cross linked fibrin
38
Q

Haemophilia A

A

x-linked recessive disorder deficiency in factor VIII

39
Q

Haemophilia B/Xmas disease

A

x-linked recessive disorder deficiency in factor IX

40
Q

Von willebrand’s disease

A

Type 1 (most common), type 2 (moderate), type 3 (Virtually no vWF)

41
Q

Congenital platelet disorders

A

Bernard Soulier: Platelet membrane disorder

Grey platelet syndrome (Storage granules)

COX and thromboxane synthetase deficiency

42
Q

Congenital platelet disorders

A

Bernard Soulier: Platelet membrane disorder

Grey platelet syndrome (Storage granules)

COX and thromboxane synthetase deficiency